Changing trends in designing space electronics

Article By : Rajan Bedi

Space technology and satellite-based applications have become ubiquitous, impacting our daily lives and being used to provide a sustainable future for us all.

Today, 57% of the world’s population, over 4 billion people on our planet, do not have access to broadband internet and commercial satellite operators are targeting this lucrative market by launching thousands of small low-Earth-orbit (LEO) spacecraft. This also represents a huge untapped opportunity for the traditional on-line giants.

Developing countries and emerging markets in Asia, South America, and Africa are seeking low-cost Earth-observation capability for national capacity building, and the desire to become self-sufficient for data collection to address local societal needs such as environmental monitoring, measuring climate change, global warming, disaster management, deforestation, imaging to locate natural resources like oil and gas, as well as observing geological formations.

Editor’s Note: The development of reusable rockets is lowering barriers to both scientific and commercial exploration of space, stimulating increasing interest and investment in space electronics. This article is part of an AspenCore Special Project that provides designers with a look at the technologies and design practices needed for creating space-worthy electronic designs, including ICs, ASICs, flex-cable, connectors, thermal management, rad-hard techniques, space-related testing methods, and more.

Global population is predicted to increase to almost 10 billion people by 2050, requiring food production to increase by 70%. At the same time, the amount of land available to grow crops is declining rapidly, with 95% of the world’s fare grown in soil. It is, therefore, incumbent that fields are used as efficiently as possible to guarantee security of the food supply and long-term sustainability.

Earth-observation satellites are increasingly using hyperspectral optical and synthetic aperture radar imagers to measure the sunlight reflected by plants (greenness), fluorescence (productivity/growth rate of each plant), and soil quality to optimise yields. These observations are complemented by IoT sensors on the ground which determine soil moisture, pH, and leaf wetness, providing farmers near real-time status of the cultivation of their fields. If data suggests they need to spray their plants with water, fertiliser, or pesticides, growers can combine the results with GPS data to instruct tractors how much treatment to apply at which rate at every point, enabling true-precision farming.

To guarantee security of the food supply and long-term sustainability, the situation at sea is equally dim: it is estimated that up to 20% of all fish caught were caught illegally, depleting the world’s oceans of their precious marine stocks. Today, over 1 billion people in developing countries rely on fish as their primary source of protein. Satellites allow real-time monitoring of vessels, fishing methods, and suspicious behaviour using optical, infrared, and SAR sensors in all weather conditions and also at night.

Today, almost 50 billion devices are connected to the internet and M2M satellite-based IoT is being sought to connect and provide continuous, real-time monitoring of critical systems in remote areas, e.g. checking land-transport cargo logistics, maritime identification and location tracking, observing animal and equipment movements, and asset supervision.

Satellite navigation provides real-time, location-based monitoring and precise timing services used by emergency services, and the transport, agriculture, fishing, civil engineering, and banking industries for a multitude of applications.

Space technology and satellite-based applications have become ubiquitous and Morgan Stanley recently valued tomorrow’s space economy at $1 trillion by 2040.

As launch costs continue to drop, traditional and new private operators of satellites are demanding lower-cost access to space to provide space-based solutions to address the above societal needs. To address these opportunities, over the last decade, several thousand commercial space companies have been founded around the world.

Space electronics has moved-on considerably from the bespoke, radiation-hardened guidance computer and hand-woven memories used on the Apollo missions. Today’s avionics are millions of times more powerful than that used to land man on the moon!

Figure 1 Apollo guidance computer and its hand-woven rope memory.

Traditional satellite transponders have an analog, RF bent-pipe architecture for telecommunication and broadcast television applications that receive the uplink information and then convert its carrier frequency for downlink as illustrated below.

Figure 2 Analogue, bent-pipe transponder

The latest payloads are much more sophisticated, offering re-generative options that demodulate on-board to improve SNR, digital beamforming techniques to steer and optimise performance in response to changing link requirements, and the ability to remove traditional frequency conversion by directly digitising and re-constructing IF/RF carriers. Conventional satellite communication is becoming congested and operators are moving to higher frequencies such as Ku, K, Ka, O, and V-band to avail of wider bandwidths to deliver the latest high-throughput services, e.g. real-time, high-definition Earth observation.

Figure 3 Digital satellite transponder

The harsh environment of space can wreak havoc on unprotected electronics; continued exposure to energetic particles gradually degrades device performance ultimately leading to component failure. Cosmic rays speeding through space can strike at sensitive locations, causing immediate single-event-effects (SEEs). Heavy ions, neutrons, and protons can scatter the atoms in a semiconductor lattice, introducing noise and error sources.

Vacuum is an inherent feature of space and materials sublime and outgas: space micro-electronics are available in both plastic and ceramic-package options to satisfy the reliability needs of all mission types.

[Continue reading on EDN US: Space electronics reliability]

Dr. Rajan Bedi is the CEO and founder of Spacechips, which provides ultra-high-throughput on-board processing and transponder products, design consultancy in space electronics, training, technical-marketing and business-intelligence services.

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